Beena Johnson, MBBS, DCH, MD,
PhD
Baby Memorial Hospital, Kozhikode, Kerala, India. PIN: 673004
Address for Correspondence: Dr.
Beena Johnson, MBBS, DCH, MD, PhD, Senior Consultant,
Department of Child Guidance, Baby Memorial Hospital,
Kozhikode, Kerala, India. Email: jiacam@gmail.com
Abstract
Children with learning disabilities have significant
impairment in reading, writing and mathematics, in spite of
normal intelligence and sensory abilities. In reading
disability, children will have difficulties in phonemic
sensitivity, phonetic decoding, word recognition, word
decoding skills and reading comprehension. The lifetime
prevalence of learning disability is about 10%. Learning
disabilities are more frequently seen in boys compared to
girls. There are several risk factors for learning
disabilities. Low birth weight, preterm birth, neonatal
complications, language delay and epilepsy are important risk
factors for learning disabilities in children. Students with
learning disabilities have poor scholastic performance,
anxiety and significant stress. They have more social,
emotional and behavioural problems than those without learning
problems. If not remedied at the earliest, learning
disabilities will lead to failure in exams and these children
may develop stress related disorders. Hence all children with
learning problems should be evaluated scientifically at the
earliest, for identification of learning disability. By
providing scientific guidance and intensive one to one
remedial training, learning problems of children can be
managed successfully.
Keywords: Learning Disability, Children, Epidemiology,
Risk Factors, Early Intervention
Introduction
Learning disabilities are developmental disorders
characterized by severe difficulties in reading, writing or
performing arithmetical calculations, in spite of adequate
instruction, intact hearing and vision as well as social
opportunity [1]. The difficulty in learning is not due to
intellectual deficit, emotional disturbance or cultural
difference [2]. They have normal intelligence and sensory
abilities.
Specific reading disability or developmental dyslexia is a
disorder in which children have significant and persistent
deficits for reading [3,4]. Reading skills develop only with
direct instruction. Phonemic sensitivity, phonetic decoding,
word recognition, word decoding skills and reading
comprehension develop in stages. If the initial skill is not
developed, further skills will not develop without scientific
remedial training [5].
The school grades of children with learning disabilities will
be low and are not comparable with their intelligence [6].
Early diagnosis and individualized remedial training are
necessary to manage the learning problems of children.
Parental guidance is essential in the diagnosis and therapy of
these children [7].
Several research studies relating to learning disabilities
have been conducted in countries all over the world. The
research studies have reported the epidemiology, risk factors
and importance of early intervention. In India also many
researches were done on children with learning disabilities
and standardized tools have been developed for assessment and
remediation [8].
Epidemiology
Learning disabilities are common among children. 12.97 per
cent of rural primary school children having IQ greater than
or equal to 90 were found to have poor academic achievement
[9]. Studies conducted to determine the prevalence of learning
disabilities have reported prevalence rate ranging from 3-10
per cent among students of India. 1.58 per cent of 12 to 18
year old school students, had specific learning disability in
a study conducted in Chandigarh. In this study, the prevalence
rate was low due to non-availability of standardized tests in
vernacular language [10]. The lifetime prevalence of learning
disability was 9.7% in children of United States of America.
Learning disability is considered as a significant morbidity
in average-developing children [11].
In a study to assess the prevalence of learning disabilities
in 3rd and 4th grade students of government schools in a
northern city of India, 33.6% of children were identified by
teachers as at-risk students. 3.08% of students were confirmed
as having learning disability [12]. Shaywitz BA et al reported
that reading disability or dyslexia is the most common of the
learning disabilities and represents a disorder of cognitive
functioning [13]. Shaywitz SE also reported that dyslexia is
the most common type of learning disability seen in children
[14]. There is strong evidence that Chinese, Japanese and
American children have reading disability. But there are
differences in the incidence of reading disability in Western
and Asian languages and this difference is related to
orthographic factors [15].
The incidence rates of reading disability in school children
varied between 5.3% to 11.8% [16]. Reading disability
was clearly more frequent in boys than in girls [17]. Four
independent epidemiological studies have proved that the rates
of reading disability are significantly higher in boys
compared to girls [18]. Boys and girls were differentially
susceptible to risk factors in reading disability. The
biologic factors leading to reading disability were different
among boys and girls [19].
Study by Mayes SD et al found that disorder of written
expression is more common than reading disability and
mathematics disability [20]. Katusic SK et al found that
disorder of written expression is almost as frequent as
reading disability, in the population-based birth cohort of
school-aged children. Disorder of written expression was seen
2 to 3 times more in boys compared to girls [21]. Boys were
consistently more impaired than girls in orthographic skills.
This could be the cause of gender differences in writing
skills [22]. The incidence of dysgraphia among school children
in India was 14%, and of dyscalculia was 5.5% [23,24].
Mathematics learning disability is common among school
children and is more frequently seen in boys. Many children
with learning disability in mathematics did not have comorbid
reading disorder [25].
Risk Factors
Reading disability (dyslexia) arises from deficits in
phonologic awareness [26,3]. Girls with low birth weight
were more than twice at risk for developing reading
disability. Girls whose mothers had 12 or fewer years of
education were twice as likely to develop reading disability
[19]. In the study conducted among fifth-grade children with
reading disability, in Japan, Taiwan, and United States,
Stevenson HW et al found that combined effects of general
information and verbal memory was the most effective
predictors in Japan and Taiwan. The most important predictors
for reading disability in American children were deficits in
general information and coding [15].
There is increased prevalence of developmental comorbidities
in children with epilepsy. There was high comorbidity of
reading disability in children with rolandic epilepsy. The
risk factors for reading disability in rolandic epilepsy
included male sex, speech sound disorder and attention deficit
hyperactivity disorder [27]. Siblings of patients with
rolandic epilepsy are also at increased risk of reading
disorder. Hence patients with rolandic epilepsy and their
younger siblings need screening and intervention at early age
to prevent reading disorder [28]. There is genetic basis for
reading disability in rolandic epilepsy with loci at 1q42. The
loci is at 7q21 in some populations [29].
Children with birth weight less than 2000 grams have poor
visuo-motor perception and are at risk for developing reading
disability and mathematics learning disability. The preterm
children who are small for gestational age, as well as
children with very low birth weight usually have poor
cognitive abilities compared to children with normal birth
weight [30].
Children with extremely low birthweight without gross physical
impairments are at higher risk for developing learning
disabilities. They are also prone to have cognitive
deficiencies. Hence these children at risk should be
identified early and learning problems should be managed
scientifically [31].
Children with very low birth weight (<1500 grams) have
higher risk for mathematics learning disabilities than
children with normal birth weight. Children with very preterm
birth (<32 weeks gestational age) are at greater risk for
developing mathematics disorder compared to term-born children
(>36 weeks gestational age). Along with mathematics
disorder, other learning problems are also seen in these
children. Children with neonatal complications are also at
risk for developing mathematics disorder [32]. Results of a
prospective longitudinal study involving 922 neonatal at risk
children conducted in South Germany showed that with lower
gestational age, the risk for mathematic impairment increases
[33].
History of language delay, confusing words that sound alike
and family history of reading disability are important red
flags for dyslexia [14]. Deficiencies in encoding processes,
especially working memory, are found in children with learning
disability [34].
Recognition of risk factors will help teachers, parents and
professionals in health care to direct these children for
early intervention. This will reduce additional cognitive
challenges for these children [5].
Importance of Early Intervention
Recent advances in child development have revealed that a
child's early experience significantly affects the learning
trajectory of that child. The limitations in social and
cognitive development of the children entering kindergarten
schools can be significantly reduced or eliminated through
early identification and developmental interventions starting
from infancy. The physical, social-emotional, and educational
health of all children should be promoted from birth [35].
Prevention is always better than cure. An expert in child
guidance can identify the deficits in phonological awareness
in late kindergarten and early interventions can be provided
to prevent reading disorder.
Most of the children with learning disabilities have deficits
in basic reading skills. Severe reading disorder is a major
problem for students especially if associated with attention
deficit hyperactivity disorder. Even mild deficits in reading
skills can cause problems in learning. Hence mild defects in
reading should also be identified early and appropriate
remedial intervention should be provided [2].
In a study involving 2,464 Norwegian adolescents of 12-15
years of age, reading difficulties were found in 7.8% of
adolescents. These adolescents had higher levels of
depression. They had more school stress and they worried more
about going to school. Adolescents with reading difficulties
also had lower score on Global Self-worth and on Social
Acceptance scales [36]. Hence they need early remedial
training and scientific guidance.
Students with learning disabilities have chronic academic
underachievement and significant stress. Learning-disabled
students have more anxiety compared to their peers [37].
Individuals with reading disability have more social,
emotional and behavioural problems than those without reading
problems [38]. Learning disabled children have adverse
emotional outcomes due to academic stress which should be
prevented [6]. Learning disorders cause significant negative
impact on the emotional, behavioural and educational
functioning of adolescents. Counselling given to adolescents
will help them to deal with the stresses associated with
learning disabilities [39].
Scientific guidance and remedial education with parent
involvement should be provided for children with learning
disabilities to improve their scholastic performance [40].
Multifactorial evaluations should be done and individualized
education plan must be formulated for these children with the
help of experts in the field of learning disability [41].
Improved academic outcome will increase the self-esteem of
children. Hence, early identification and intervention of
learning disability is essential [12,42,43].
It is very important to identify learning disability early and
start intervention soon, because the longer these children go
without identification, remediation will be more difficult and
the rate of success will be lower [6,14]. All at risk children
must be screened for developmental and learning problems. The
students with learning problems should be given appropriate
educational interventions. All parents and children who have
concerns about school performance need evaluation by experts
and scientific interventions must be started as early as
possible [44].
Conclusion
Learning disability is common among children and it is an
important cause of stress. Delay in expressive language
development can lead to learning disability in the future and
hence early intervention by experts in child guidance is
necessary.
If not remedied at the earliest, learning disabilities will
lead to failure in exams and can cause emotional and
behavioural problems in children. These children also develop
stress related disorders. Hence all children with learning
problems should be evaluated scientifically for early
identification of learning disability.
Scientific guidance to improve the coping skills, should be
given to children and adolescents with learning disabilities
to deal with the academic stress. Early intensive
individualised remedial education should also be provided on
one to one basis to manage the learning disability.
Students of today are the budding futures of all nations. In
human resource development, education has a very important
role. Hence there is urgent need to increase awareness
regarding learning disabilities of children, among parents and
teachers. The learning disabilities of children should be
identified at the earliest and managed scientifically so that
we can lead the children towards a very successful future
life.
References
1. Karande S, Kulkarni M. Specific learning disability: The
invisible handicap. Indian Pediatr.2005;42:315-9.
2. Lyon GR. Learning disabilities. Future Child. 1996
Spring;6(1):54-76.
3. Demonet JF, Taylor MJ, Chaix Y. Developmental dyslexia.
Lancet. 2004 May 1;363(9419):1451-60.
4. Billard C1, Delteil-Pinton F. Dyslexia: clinical
characteristics. Arch Pediatr. 2010 Dec;17(12):1734-43.
5. Grizzle KL. Developmental dyslexia. Pediatr Clin North Am.
2007 Jun;54(3):507-23.
6. Shapiro BK, Gallico RP. Learning disabilities. Pediatr Clin
North Am 1993; 40: 491-505.
7. Lagae L. Learning disabilities: definitions, epidemiology,
diagnosis, and intervention strategies. Pediatr Clin North Am.
2008 Dec;55(6):1259-68.
8. Ramaa S. Two decades of research on learning disabilities
in India. Dyslexia. 2000 Oct-Dec;6(4):268-83.
9. Agarwal KN, Agarwal DK, Upadhyay SK, Singh M. Learning
disability in rural primary school children. Indian J Med Res.
1991 Apr;94:89-95.
10. Arun P, Chavan BS, Bhargava R, Sharma A, Kaur J.
Prevalence of specific developmental disorder of scholastic
skill in school students in Chandigarh, India. Indian J Med
Res 2013;138:89-98.
11. Altarac M, Saroha E. Lifetime prevalence of learning
disability among US children. Pediatrics. 2007 Feb;119 Suppl
1:S77-83.
12. Padhy SK, Goel S, Das SS, Sarkar S, Sharma V, Panigrahi M.
Prevalence and Patterns of Learning Disabilities in School
Children. Indian J Pediatr. 2016 Apr;83(4):300-6.
13. Shaywitz BA, Fletcher JM, Shaywitz SE. Defining and
classifying learning disabilities and
attention-deficit/hyperactivity disorder. J Child Neurol. 1995
Jan;10 Suppl 1:S50-7.
14. Shaywitz SE. Dyslexia. N Engl J Med 1998; 338:307- 312.
15. Stevenson HW, Stigler JW, Lucker GW, Lee S, Hsu C,
Kitamura S. Reading disabilities: the case of Chinese,
Japanese, and English. Child Dev. 1982 Oct;53(5):1164-81.
16. Katusic SK, Colligan RC, Barbaresi WJ, Schaid DJ, Jacobsen
SJ. Incidence of reading disability in a population-based
birth cohort, 1976-1982, Rochester, Minn. Mayo Clin Proc 2001;
76:1081-1092.
17. Liederman J, Kantrowitz L, Flannery K. Male vulnerability
to reading disability is not likely to be a myth: a call for
new data. J Learn Disabil. 2005 Mar-Apr;38(2):109-29.
18. Rutter M, Caspi A, Fergusson D, Horwood LJ, Goodman R,
Maughan B, Moffitt TE, Meltzer H, Carroll J. Sex differences
in developmental reading disability: new findings from 4
epidemiological studies. JAMA. 2004 Apr 28;291(16):2007-12.
19. St Sauver JL, Katusic SK, Barbaresi WJ, Colligan RC,
Jacobsen SJ. Boy/girl differences in risk for reading
disability: potential clues? Am J Epidemiol. 2001 Nov
1;154(9):787-94.
20. Mayes SD, Calhoun SL, Crowell EW. Learning disabilities
and ADHD: overlapping spectrum disorders. J Learn
Disabil. 2000;33(5):417-24.
21. Katusic SK, Colligan RC, Weaver AL, Barbaresi WJ. The
forgotten learning disability: epidemiology of
written-language disorder in a population-based birth cohort
(1976-1982), Rochester, Minnesota. Pediatrics.
2009;123(5):1306-13.
22. Berninger VW, Nielsen KH, Abbott RD, Wijsman E, Raskind W.
Gender differences in severity of writing and reading
disabilities. J Sch Psychol. 2008 Apr;46(2):151-72.
23. Shah BP, Khanna SA, Pinto N. Detection of learning
disabilities in school children. Indian J Pediatr 1981; 48:
767-771.
24. Ramaa S, Gowramma IP. A systematic procedure for
identifying and classifying children with dyscalculia among
primary school children in India. Dyslexia 2002; 8: 67-85.
25. Barbaresi WJ, Katusic SK, Colligan RC, Weaver AL, Jacobsen
SJ. Math learning disorder: incidence in a population-based
birth cohort, 1976-82, Rochester, Minn. Ambul Pediatr.
2005;5(5):281-9.
26. Gabrieli JD. Dyslexia: a new synergy between education and
cognitive neuroscience. Science. 2009 Jul 17;325(5938):280-3.
27. Vega YH, Smith A, Cockerill H, Tang S, Agirre-Arrizubieta
Z, Goyal S et al. Risk factors for reading disability in
families with rolandic epilepsy. Epilepsy Behav. 2015
Dec;53:174-9.
28. Clarke T, Strug LJ, Murphy PL, Bali B, Carvalho J, Foster
S et al. High risk of reading disability and speech sound
disorder in rolandic epilepsy families: case-control study.
Epilepsia. 2007 Dec;48(12):2258-65.
29. Strug LJ, Addis L, Chiang T, Baskurt Z, Li W, Clarke T et
al. The genetics of reading disability in an often excluded
sample: novel loci suggested for reading disability in
rolandic epilepsy. PLoS One. 2012;7(7):e40696.
30. Chaudhari S, Otiv M, Chitale A, Pandit A, Hoge M. Pune low
birth weight study--cognitive abilities and educational
performance at twelve years. Indian Pediatr. 2004
Feb;41(2):121-8.
31. Litt J, Taylor HG, Klein N, Hack M. Learning disabilities
in children with very low birthweight: prevalence,
neuropsychological correlates, and educational interventions.
J Learn Disabil. 2005 Mar-Apr;38(2):130-41.
32. Taylor HG, Espy KA, Anderson PJ. Mathematics
deficiencies in children with very low birth weight or very
preterm birth. Dev Disabil Res Rev. 2009;15(1):52-9.
33. Jaekel J, Wolke D. Preterm birth and dyscalculia. J
Pediatr. 2014 Jun;164(6):1327-32.
34. Denckla MB. Biological correlates of learning and
attention: what is relevant to learning disability and
attention-deficit hyperactivity disorder? J Dev Behav Pediatr.
1996;17(2):114-9.
35. High P, Donoghue E, English KL, Fussell J, Jaudes PK,
Jones VF et al. School readiness. Pediatrics. 2008
Apr;121(4):e1008-15.
36. Undheim AM, Sund AM. Psychosocial factors and reading
difficulties: students with reading difficulties drawn from a
representative population sample. Scand J Psychol. 2008
Aug;49(4):377-84.
37. Thakkar AN, Karande S, Bala N, Sant H, Gogtay NJ,
Sholapurwala R. Is anxiety more common in school students with
newly diagnosed specific learning disabilities? A
cross-sectional questionnaire-based study in Mumbai,
Maharashtra, India. J Postgrad Med. 2016 Jan-Mar;62(1):12-9.
38. Terras MM, Thompson LC, Minnis H. Dyslexia and
psycho-social functioning: an exploratory study of the role of
self-esteem and understanding. Dyslexia. 2009;15(4):304-27.
39. Kelly DP. Learning disorders in adolescence: the role of
the primary care physician. Adolesc Med State Art Rev. 2008
Aug;19(2):229-41.
40. Lambros KM, Leslie LK. Management of the child with a
learning disorder. Pediatr Ann. 2005 Apr;34(4):275-87.
41. Schulte EE. Learning disorders: How pediatricians can
help. Cleve Clin J Med. 2015 Nov;82(11 Suppl 1):S24-8.
42. Nitasha S, Sangwan S. Extent of learning disabilities and
risk factors. Disabil Impair.1999;13:105-10.
43. Al-Otaiba S. Children who do not respond to early literacy
instruction: a longitudinal study across kindergarten and
first grade. Read Res Q. 2001;36:344-9.
44. Kelly DP, Aylward GP. Identifying school performance
problems in the pediatric office. Pediatr Ann. 2005
Apr;34(4):288-98.